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Letters Patent No. 90,794, dated June 1, 1869.

, VIMIIPROVEMIENl IN STElAM-GENERATOR SAFETY-VALVES.

The Schedule referred to in these Letters Patent and making part of the same.

To all rvwm 'it may concern Be it known that we, HENRY TAYLOR and JOSEPH M. COALE, of the city of Baltimore, and State of Figure l represents avertical section through the safety-valve. A

. Figure 2 represents a top view of the same.

Similarletters of reference, where they occur in the drawings, denote like parts in both figures. Y

The object of our mventlon is a safety-valve for steam generators, constructed as hereinafter desclibed, which will blow olf steam automatically, at any press ure for which it may be set; and which the attendant can cause to blow o steam at any time, to relieve the pressure in the boiler, or to testthe operation of the valve, but which yhe cannot weigh down, or prevent escaping steam at the pressure for which it was originally set before it was closed up, and therefore cannot be tampered with by him, to increase the pressure in the boiler.

To enable others skilled in the art to make and use our invention, weAwill proceed to describe the same with reference to the drawings.

A represents thedome of a boiler, upon which is placed the perforated casting B, which supports the different valves composing our safety-valve, as will be described hereafter, this casting and valves being covered bythe cap-piece C, which is, with the casting B, fastened to the dome A by screws a and packing, as used in ordinary steam-joints.

Inside of the dome A is a weight, D, fastened to the lower end of the' valve E, which keeps this valve p on its bearings b. The weight of the valve E, with its weight D, is computed for the amount of pressure that the safety-valve is to bear before it blows o.

This valve E rests, by its bearings b, on the intermediate or reciprocatingvalve F, which is kept up against its seat c by the steam acting on the under side of it, and also by the spring d, which keeps it closed before steam is made, in this manner obviating any loss of steam from the beginning.

When the pressure of steam inthe boiler is greater than that for which the weight D and valve E is regulated, the weight and valve -will be raised, and steam will escape in the steam-passage G, and as the steam escapes from under the valve F, said valve will cushion down upon the steam, and open the passage c, and

the latter will escape through the steam-passage G and holes f, to the open air.

Above the valve F is placed the valve H, which is at first kept up against 'its seat g' by the spring h, and

also, when steam is raised up, by the action of the steam against its under side; but when the passage c is opened lfor the escape of steam, as mentioned above, and escapes from under the valve H, said valve will cushion down upon the steam, and open a passage at g,'for its escape to the open air.

The valve E, when resting upon its seat b, is als supported by the pin t', which keeps the valve E and weight D from drawing the valve F 0E -its seat.

The weight D and valve E can also be supported by the eccentric, K, attached'to the rod L; 'but the main object ofthe eccentric, K, is `to raise the weight D and valve E olf its seat, when it is desired to blow oi steam, for which purpose it is operated by means of the hand-lever M.

When the pressure in the boiler falls below the at- I mospheric pressure, the valve H is pressed down by the atmosphere, and air enters the boiler, till an equilibrium is established in the pressure of the inside and outside of the boiler, thereby preventing any collapse or strain of the boiler. Y

The operation is as follows:

Steam being raised in the boiler, it fills up the dome A, and also the interior'of the cap O, from which it passes under the valve H, through the passage l, bctween the casting B#and valve H. From this space it passes under the valve F, through the passagem, formed by fitting loosely the valve F to the casting B. From thence the steam acts on the valve E, ready to raise it, when its power will be greater than the counter-acting weight D, when the valve E will Ybe raised, allowing the steam to escape from under/thavalve F. Said valve will then cushion down upon the steam and open the passage c, which will allow the steam to escape from under the valve H, when this last valve will Y also cushion down upon the steam, and open -the passage g, and allow the steam to escape in the-air.

Having thus fully described our invention, l v What we claim therein as new, and desire to secure by Letters Patent, is I 1. The intermediate or reciprocating valve F, in combination with the steam-passage G and perforations f, for the escape of steam, substantially as set forth. v

2. The valve H, as constructed, with the steampassage G, running through its centre, and the perforations f, through its top, substantially as described 3. The combination of the valves E F H, with each other and with the steam-passages, substantially as described. ,Y

HENRY TAYLOR. J. M. COALE.

Witnesses:

A. B. STOUGHTON, EDMUND Masson. 

